Hot top



E. A. MARCEC Dec. 26, 1961 HOT TOP Filed Deo. 4, 1958 mc WE E6 Vm mM A.W V R E Stats This invention relates in general to the metal pouring artand more particularly to hot tops. Specifically, it relates to acomposite refractory bottom ring for hot tops and method formanufacturing same.

' A hot top is an insulated and inverted funnel-like de vice which ispositioned over a mold with its lower end extending slightly into themouth of the mold. Metal is poured from ladies or the like through suchdevices and hot tops are particularly employed iu the pouring of ironand steel into ingot molds. It is well known that as molten metal coolsand solidifies in a mold it contracts, leaving a trough-like depressionin the upper surface of the ingot, billet or other object thus formed.Extensive cropping of the entire upper surface of the molded object tothe depth of the depression or cavity thus formed is usually necessary,It is expedient, therefore, to provide above such molds a reservoir ofmetal in molten condition so that as the metal in the mold chills andcontracts, fresh metal will continue to be fed in by gravity, so thatultimately instead of an extensive cavity in the top of the moldedarticle, only a comparatively small riser results after any excessreservoir material has chilled. The cropping of such a riser is arelatively simple matter. Since such a reservoir atop the mold isrequired to maintain a supply of metal in molten form during thechilling of the article being formed, it is well insulated and thus itsname hot top.

Hot tops generally take the form of hollow steel casings provided with alower inturned lip. This lip is provided to support refractory materialwhich lines the inner walls of the steel casing protecting andinsulating the casing. As the lower end of the steel casing of the hottop must be lowered into the mouth of the mold, it is dimensioned sothat suitable clearance is provided between the outside of the base ofthe hot top casing and the mouth of the mold. ternal of the lowerinturned steel lip of the hot top casing must also be insulated andprotected from the molten metal which rises in the mold just as theinner walls of the casing are protected and insulated, and this isaccomplished by means of a refractory ring which is secured to thebottom of the hot top casing.

These refractory rings generally conform in shape to the externaloutline of the base of the hot top and are provided with a smallupwardly extending rim dening a central opening and to protect theinternal of the inturned lower lip of the steel casing of the hot top.This refractory rim extends into the casing and approximately abuts therefractory lining of the hot top casing. Such refractory ring devicesare suspended by hook-like wire hanger clips, one or two to a side,which hook under the refractory ring and at the other end are insertedinto apertures provided for that purpose in the side walls of the steelcasing of the hot top. In an effort to prevent metal from spewing out ofthe mold through the clearance space between the lower end of the hottop casing and the mouth of the mold, the general practice has been toinsert or sandwich thin flexible sheet metal wiper strips between thebase of the steel hot top casing and the upper surface of the refractoryring with a slightly upturned lip portion extending outwardly to engagethe walls of the mold.

ln practice a hot top is prepared for a molding operation by invertingit about external trunnions usually provided on its casing for thatpurpose. The refractory ring the wiper strips from being pushed too farinwardly between these two surfaces. These generally take the form of ashoulder or other type of identation formed into the upper surface ofthe refractory ring, and more re- Moreover, the bottom and in cently ametal pin extending into the upper surface of the refractory ring andagainst which the wiper strip abuts. The hook-like wire hanger clips'are then applied by first hooking them over the now luppermost bottomsurface of the refractory ring through slits in the externallyprojecting wiper portions, and down the sides of the steel casing intothe appropriate apertures. Additional refractory material in the form ofgrout, referred to as much is then troweled in place to ll the gapbetween the ring and the lining of the hot top casing, and additionalmud may` be troweled over the entire refractory lining of the hot topcasing to protect the refractory lining for future pourings, the mud andthe refractory ring eing expandable with each operation.

After the mud has dried, the hot top with bottom ring attached isrotated into its normal position and ultimately lowered into the mouthof a mold. It is during this operation that the wiper strips aresubjected to outwardly and upwardly directed forces as they engage thewalls of the mold, which forces tend to pull them out, buckle them, orotherwise cause their disarrangement and consequently an imperfect seal,This is not diflicult to appreciate when it is considered that the hottop is a heavy and bulky object being handled by crane, and the onlyforces tending to hold the wipers in place against these forces is thatexerted by the hook-like hanger clips referred to above, and which areapplied in limited number, usually one or two to a side of the casing,yor in other words, only one or two clips to each individual wiper strip.

The pulling out and otherwise disarrangement of the wiper strips in thisstill widely used practice results in loss of metal, imperfect moldedobjects, damage to the thus unprotected outer surface of the steel hottop casing, and substantial hazard to operating personnel.

More recently, in my co-pending application Serial No. 483,322, filedJanuary 21, 1955, I have provided a composite refractory ring in whichthe thin sheet metal wiper strips are provided with lugs which aredepressed into a surface of the refractory ring in a manner such thatthe collar portion from which the lugs depend overlieS the embeddingsurface of the refractory material and the flange portion extendsoutwardly beyond the outer periphery of the refractory ring material. Inthat application, the wiper strip was preferably attached to the uppersurface ofthe refractory material, and after the latter had been formed,rammed, baked, red or otherwise cured, the wiper strip became integrallyconnected thereto by virtue of the embedded depending lugs.'Conventional hanger clip means, however, were contemplated in thatapplication to suspend such a composite ring from the hot top. l

The use of conventional hanger clips, even with my composite ring devicereferred to above as copending, is subject to a serious disadvantage.Frequently when these conventional hanger clips are snapped in place,care is not taken by the unskilled foundry labor to insure that theunderside of the hanger clips are fully snapped into the recessesprovided for that purpose in the underside of the refractory ring. Also,it often happens in careless assembly at the use site that the hangerclip is not positioned properly to pass through the slits in the wiperstrips provided for that purpose. In situations like this, not only arethe wiper strips likely to be disarranged when the hot top is loweredinto the mouth of the mold, but should the original pass result in thesetting of the hot top in an improper position, lopsided or at an anglefor instance, it is necessary to pull the hot top back up and out of themold for another pass by the crane, which is supporting it, to positionit correctly. It is under these circumstances of withdrawal forrepositioning that the wipers are subjected to the most severe crushingforces and likewise severe tensions are put on the hanger clips. Notinfrequently, the improperly arranged hanger clips then pull away fromthe bottom of the ring so that top. These are called hangers `as thering then hangs in the mold, causing an improper molded product, in

addition to damage to the hot top and danger to the d workmen fromspewing hot metal.

The present invention constitutes an improvement over and continuationof my referred-to copending application in that I have now provided forthe embedment at least partially of both the metal wiper strips and thehanger clips. Additionally, I have provided hanger clips preferably ofspring steel wire formed with a plurality of legs doubling back one overanother and which legs are integrally joined by loops thus providing thehanger clip capable of yieldable extendability and limited movement ofthe free end. One end of these hanger clips is embedded in therefractory material so that it cannot be pulled away, while the other orfree end is provided with an inturned hooklike projection adjacent whichthere is preferably located another loop for ease in handling anddirecting the projection into engagement with a suitable aperture in theside wall of the hot top casing. In the preferred embodiment, I haveprovided the collar portions of my wiper strips with a plurality ofapertures or holes, and I embed this portion in the outer side walls ofthe refractory material so that when rammed, the refractory isintegrally connected to the embedded wiper strip through the apertures.The embedded end of each of the specially formed hanger clips is alsosuitably formed, preferably in the form of a hook or loop, so that whenit has been inserted also preferably in the outside walls of therefractory material, and above the level at which the collar portions ofthe wiper strips are inserted, and the refractory is rammed, it too willbe integrally connected and embedded therewithin. In the preferredembodiment, it will be seen therefore that the flexible ange portion ofthe wiper strip extending externally of the refractory requires no slitsfor the passage of hanger clips and thus an optimum seal is obtained.

With my present invention not only are all of the objections overcomewith respect to the tendency for wiper strips and the hanger clips tobuckle and pull out or away due to forces acting upon them in thepositioning of the hot top within the month of a mold, and which isinherent in nonintegrally connected and nonembedded wiper strips andhanger clips, but I have also now provided a composite device which isfully prefabricated away from the location of use and shipped ready foruse, so that all that need be done except for later application of mudinternally is to position the composite device inverted over theinverted end of the hot top and to extend and position the integrallyattached hanger clips to snap into the respective openings, thuseffecting a substantial time and labor saving while assuring an absolutetit and uniform suspension of the refractory ring from the base of thehot top casing.

It is accordingly the principal object of this invention to provide acomposite refractory ring for hot tops, in which both the wiper stripsand the hanger clips are at least partially embedded and integrallysecured to the refractory material so that the possibility of humanerror the ring is no longer properly suspended from the hot inpositioning and suspending same from a hot top is eliminated.

It is another object of the invention to provide the collar portions ofthe Wiper strips with a plurality of apertures and to embed such collarportions in the refractory material, whereby upon ramming and curing,said wiper strips are integrally attached and connected to therefractory material through the referred-to apertures.

It is still another object of this invention to embed one end of thehanger clips within the refractory material at a level above that atwhich the wiper strips are embedded.

Yet another object of this invention is to embed both the collarportions of the wiper strips and the lower ends of the hanger clips inthe outer side Walls of the refractory ring above its base.

Still another object of the invention is to also provide within saidrefractory ring additionally embedded reinforcing material integrallyconnected to the refractory by means of suitable apertures in thereinforcing material.

Another object of this invention is to provide a method for fabricatinga composite refractory ring in which both metal wiper strips and hangerclips are embedded at least in part and integrally attached to therefractory material.

These and additional objects and advantages will become more readilyapparent from the following descripion taken in conjunction with theaccompanying drawings, in which:

FIGURE l is a perspective view of a composite refractory bottom ring forhot tops illustrating a combination in which both metal wiper strips andhanger clips are embedded at least in part and integrally connected tothe refractory material.

FIGURE 2 is a section along line 2--2 of FIGURE 1 and illustratesspecifically the manner in which the metal wiper strips and hanger clipsare embedded within and integrally attached to the refractory material.It also illustrates metal reinforcing embedded and anchored within therefractory material.

FIGURE 3 is a partial elevation viewed along line 3--3 of FIGURE l.

FIGURE 4 is a view similar to that of FIGURE 3 but illustrating asimilar portion of the composite refractory bottom ring in placesuspended from a corresponding portion of a hot top casing by itsembedded and integrally connected hanger clips.

FIGURE 5 is a somewhat schematic sectional view illustrating a compositebottom ring including the ernbedded and integrally connected Wiperstrips and hanger clips suspended from the casing of a hot top and Setin place in the mouth of a mold.

Referring now more particularly to FIGURE l, the reference Acharacter 10generally designates a composite refractory bottom ring for a hot topembodying applicants invention. The refractory bottom ring 10 involvesan otherwise conventionally shaped bottom ring of suitable refractorymaterial such as a mixture of silica sands and sodium silicate binder,having a lip-like base 11 which extends laterally outwardly from anopstanding rim 12 which defines a central opening 13. Along theperipheral sides or edges of the base lip 11 of the refractory ring areembedded, preferably one to a side, wiper strips 15 which may beconstructed to thin gauge sheet metal material. These Wiper strips arepreferably of such length that they meet at the corners the wiper stripsfrom the adjacent sides. These wiper strips include a collar portion 16(see FIG. 2) provided with a plurality of anchoring means 17, which inthe preferred embodiment take the form of cut-outs or holes 17.Extending outwardly and preferably upward at a slight angle from thecollar portions 16 are flanges 18 which are preferably integrallyattached to the collar portion 16.

In the formation of the refractory material forming the base lip 11 andupstanding rim 12, these Wiper strips are inserted and embedded into therefractory material at least in part, and preferably to the full extentof the collar portions. After the refractory material is rammed inconventional manner, it extends integrally joined above and below thecollar portion 16 and through the apertures or holes 17. When the wiperstrips 15 have been thus embedded on all lateral sides of the refractorybase lip 11 they form, except for a division at the corners, asubstantially continuous exible metal wiper or seal extending laterallyoutwardly and slightly upwardly around the entire external periphery ofthe base lip. At the same time that the refractory base lip 11 andupstanding rim 12 are being formed, it has been found preferable toinsert additional reinforcing material 2G such as thin gauge sheet metalmaterial also provided with a plurality of inter-engaging or securingmeans such as apertures or holes 21. Thus when the refractory materialis rammed in the conventional manner, it too will engage the reinforcingmaterial 20 and be integrally formed therewith through the engagingapertures or holes 21.

There are also additionally provided at the time that the refractorybase lip and upstanding rim are formed, a plurality of hanger clips 25,preferably two to a side, which are embedded and integrally attached atone end within the base lip 11 of the refractory material, andpreferably in the refractory material at a position above the level atwhich the collar portions 16 of the wiper strips 15 extend into therefractory material.

The hanger clips 25 (see FIGS. 2, 3 and 4) may be made of any suitablematerial but are generally formed of steel wire in the order of numberl2 size and preferably in the hardness range of spring steel, so thatwhen suitably looped will provide a yieldable, but strong resilientmember requiring from about 25 to 50 pounds of pressure to distend. Inthe preferred form, applicants hanger clips 25 at one end take the formof an inturned hook 26 which is embedded within and integrally connectedto the refractory material, and as stated before, preferably above thelevel at which the metal collar portions 15 of the wiper strips areembedded. External of the refractory member, the hanger clips 25 arepreferably provided with at least two somewhat lateral but transverselyextending legs integrally interconnected by a loop. As illustrated inFIGURE 2 of the portions external of the refractory material, a first orbase leg 27 extends from the embedded hook end 26 laterally external ofthe refractory base lip to the looped portion 28 which joins it and asecond generally lateral and transversely extending leg 29, whichpreferably doubles back over the lower or first leg 27. Applicant hasfound it preferable for proper support of the composite refractory ringfrom a hot top casing, and for ease of connecting thereto, to providethe leg 29 at its lother end with still another loop 3i) from whichintegrally extends a final leg 31. The leg 31, it will be observed, nowsomewhat parallels at rest the lower leg 27, and it in turn at its otherend is provided with a loop 32 which terminates in a hooklike end 33bent over the leg 31. The hooklike end 33 is adapted as the clip isstretched or extended to =be inserted or snapped into an aperture 35(FIG. 4), which is drilled or otherwise formed in the lower portion ofthe side walls of the hot top casing 36.

The general shape of the preferred form of the hanger clips 25 will benoted to be somewhat in the form of a Z or perhaps more appropriately,because of the looped interconnections of the three legs which fonn a Z,but due to the looped interconnections of the legs, might moreaccurately approach that of the written capital letter L. The loops 28and 30 contribute to the springlike resiliency so that the hanger clip25 as seen in its relaxed position in FIGURE 3 may be grasped either bythe fingers or by means of a suitable instrument, similar for example tothe buttonhook, at the loop 32 and stretched or expanded by `applicationof reasonable pressure, preferably about 35 pounds, to its extended formin which position the hooklike end 33 in inserted and snapped into theapertures 35 in the hot top casing. It will be appreciated that thepreferred form of applicants hanger clip provides a considerable degreeof latitude of movement of the hooked end 33 vertically andhorizontally, so that no difiiculty is encountered in locating andsnapping the hooked end 33 into the appropriate aperture 35 in the hottop casing.

Since the general shape of a bottom ring s rectangular and vusually twohanger clips are employed per side, the ring is suspended in' a mannerto withstand counter forces should it be necessary to pull the hot topout for repositioning of the order of 275 pounds or more, thus insuringthat it will remain properly secured to the hot top.

it will be noted also from FIGURE 3 that in the relaxed position theupper hooklike end 33 of the hanger clips 25 preferably do not extendany higher than the top surface of the 1upstanding rim 12, thuseliminating interference when the rings are stacked or otherwise placedon multiple pallets.

A hot top is rather schematically shown in section in FIGURE 5 andembodies the steel casing of a hot top 36 provided with the apertures 35referred to above and suitable external trunnions 37, about which thehot top is rotated for preparation as referred to above. Within the hottop casing 36 there is provided a suitable lining of refractory material3S defining a central opening 39. Below the hot top illustrated inFIGURE 5 there is shown the composite refractory ring as described abovesuspended from the casing by its integrally connected and embeddedhanger clips 25 and with its embedded and integrally connected wiperstrips 15 in engagement with the side Walls of the mouth of the mold 40.The refractory ring 10, with its internal opening 13 in register withthat (39) of the hot top, thus protects the lower ends of the steelcasing 36 from molten metal. For purposes of clarity, no mud is showntroweled into the spaces between the hot top refractory lining and thering.

After the metal members, such as the wiper strips 15, the reinforcingstrips 20, and the hanger clips 25, have been positioned within theshaped refractory material forming the refractory base lip 11 andupstanding rim 12 of the bot-y tom ring 10, the refractory material isrammed in conventional manner whereby it is densiiied and the metalmembers are firmly embedded therein. Thereafter, the entire composite isbaked, fired, or otherwise cured also in well known and conventionalmarmer. As pointed out earlier and well known in the art, the refractorymaterial is preferably a combination of silica sands `and water glassbinder, and the baking and curing is generally accomplished in an oven.at temperatures in the range of 50() to 800 F. and preferably at about650 F.

Upon completion of the curing period, the composite ring described aboveis a completely integrated and unitary assembly, such that neither theembedded and integrally connected wiper strips 15 nor the hanger clips25 will become dislodged `from the refractory material during shipmentor use.

It will be appreciated that numerous modifications and arrangements willbe hereby suggested to those skilled in the art. For example, differentIforms of hanger clips and different positions of the wiper strips 15relative to the base or top surface of the refractory base lip. It isalso conceivable, by revising the shape of the bottom leg at least ofthe hanger clips 25, to embed them below the level at which the wiperStrips 15 are embedded within the refractory base lip by providingsuitable laterally extending slits in the externally and slightlylupwardly projeco ing ange portions of the wiper strips. These and allauch modifications 'and arrangements as come within the spirit of thisinvention are included within its scope as best defined in the appendedclaims.

1 claim:

l. A composite refractory and metal device `for hot tops comprising thecombination with a refractory member having a base and a plurality ofexternal sides transverse to said base, of a corresponding plurality ofwiper strips comprising relatively thin gauge sheet metal having aninner collar portion provided with means for interengaging with thematerial of the refractory member, said inter engaging means comprisingsubstantial rlat surface areas embedded within said external sides ofsaid refractory member above the base and permanently bonded to saidrefractory member and a liexible portion integrally connected to andextending outwardly from said collar portion beyond the external sidesof said 'refractory member, and a plurality of yieldably extendablehanger clips each having at least a pair of overlapping legs joined byan integrally formed loop, an end embedded within and integrallyattached to a surface of said refractory member below its upper surface,and the other end provided with means for securing it to the hot top,said other end being universally adjustable within predetermined limits.

2. A composite refractory and metal device for hot tops comprising thecombination with a refractory member having ta base and a plurality ofexternal sides transverse to said base, of a corresponding plurality ofwiper strips comprising relatively thin gauge sheet metal having aninner collar portion, a port-ion at least of which is embedded withinand permanently bonded to said refractory member and a exible portionextending outwardly from said collar portion beyond the external sidesof said refractory member, and a plurality of yieldably extendable Wirehanger clips each having an end embedded within and integrally attachedto a surface of said refractory member below its upper surface, theother end provided with a hook-like projection extending inwardly oversaid refractory member for securing it and 'the wiper embeddedrefractory to the hot top, and an intermediate portion between theembedded end and the hook-like projection integrally joined therewith byat least one complete loop, said other-end being universally adjustablewithin predetermined limits.

3. A composite refractory and metal device for hot tops comprising thecombination with a refractory member having a base and a plurality ofexternal sides transverse to said base, of a corresponding plurality ofwiper strips comprising relatively thin gauge sheet metal having aninner collar portion, a portion at least of which is embedded andpermanently bonded to said refractory member and a flexible portionextending outwardly from said collar portion beyond the external sidesof said refractory member and a plurality of yieldably and extendablespring steel wire hanger clips each having a shaped end embedded withinand integrally attached to a surface ofsaid refractory member below itsupper surface, said clips having at least two legs of said clipsexternal of said refractory member, one extending outwardly and up`wardly from said embedded end, and a second leg of said clips doublingback over said first leg and joined thereto by an integrally formedloop, and Ia hook-like projection on the free end of said hanger clipsfor securing said wiper embedded refractory to the hot top, said freeend being universally adjustable within predetermined limits.

4. A composite refractory and metal device for hot tops comprising thecombination with a refractory member having a base and a plurality ofexternal sides tra-nsverse to said base, of a corresponding plurality ofwiper strips comprising relatively thin gauge sheet metal having `aninner collar portion, a portion atleast of which is embedded within andpermanently bonded rto the side walls of the refractory member and aflexible portion extending outwardly from said collar portion beyond theexternal sides of .said refractory member, and a plurality of yieldableand extendable spring steel Wire hanger clips each having a shaped endembedded within and integrally attached to a surface of said refractorymember below its upper surface, a lirst leg of said clips external ofsaid refractory member extending outwardly and upwardly from saidembedded end, a second leg of said clips doubling back over said firstleg and joined thereto by an integrally formed loop, a third leg -ofsaid clips doubling back over said second leg and joined to said secondleg by another integrally formed loop, -and a hook-like projection onthe free end of said third leg for securing said end and the wiperembedded refractory member to the hot top, said hook-like projectionbeing joined to said :third leg by an integrally formed loop forengagement by a finger or tool to extend said clip and position thehooklilre projection to engage the hot top, said free end beinguniversally adjustable within predetermined limits.

5. Method of manufacturing a composite refractory and metal device forhot tops comprising the steps of mixing particulate refractory materialwith a binder, forming said refractory and binder material into a ringhaving a base, external sides transverse to said base and an upturnedrim defining a central opening, punching apertures in a portion of eacho-f a plurality of metal wiper strips, embedding and permanently bondingsaid aper- -tured portions of -said plurality of wiper strips in theexternal sides of said refractory material, form-ing yieldablyextendable hanger clips of wire with at least two overlapping legsjoined by an integral complete loop, embedding one end o-f saidyieldably extendable hanger clips in `surfaces of said refractorymaterial below its upper surface, ramming said refractory material aboutsaid por- `tions of .the wiper strips and hanger clips extending intothe said respective surfaces of the refractory material to firmly embedthem the-rewithin, and curing said refractory to integrally attach saidembedded portions of the Wiper strips and hanger clips thereto.

6. Method of manufacturing a composite refractory and metal device forhot tops comprising the steps of mixing particulate refractory materialwith a binder, forming said refractory and binder material into a ringhaving a base, external sides transverse to said base and an upturnedrim defining -a central opening, punching apertures in a 4portieri ofeach of a plurality of metal wiper strips, embedding and permanentlybonding said apertured .portions of said plurality of wiper stirpe inthe external sides of said refractory material above the base, for-mingyieldably 'extendable hanger clips of wire with tat least two'overlapping legs integrally joined by a complete loop, each such hangerclip having formed thereon a hooked free end an an end adapted foranchoring in the refractory material, embedding and permanently bondingin said side walls of said refractory material extending below its uppersurfaces including said central opening the non-hooked ends of yieldablyextendable hanger clips `in said refractory material, ramming saidrefractory ma# terial about said portions of the wiper strips andIhanger clips extending into the refractory material to permanentlybond/them and firmly embed them therewithin and curing said refractoryto integrally attach said embedded portions of 'the wiper strips and`hanger clips thereto.

References Cited in the file of this patent UNITED STATES PATENTS MarcecDec. l, 1959

